Aircraft purposefully built to avoid radar detection are characterized by shapes with as few different angles as possible. This results in edges which are parallel to each other even if on opposite sides of the aircraft. It is also desirable to have a fuselage that is blended into the wing where any shapes of small radius can be placed on the upper side, unseen by ground radar. Because of this smooth integration, these aircraft are sometimes referred as “flying wings.” An example of a flying wing aircraft is the B-2 bomber. An aircraft of low radar cross section is devoid of any unnecessary protuberances such as a vertical stabilizer, having its function replaced by control surfaces that increase the drag on one wing or the other only when needed and otherwise lie against the wing to become part of the wing.
The advantages of all-wing, tailless aircraft are known. For example, tailless aircraft provide enhanced stealthy operating characteristics due to their inherent low-observable configuration. Moreover, all-wing aircraft provide other benefits such as improved efficiency due to reduced weight and drag and, accordingly, are well suited for use in a wide variety of applications such as in autonomous (unmanned) aircraft where the bulge for a pilot to look out doesn't have to be accommodated.
A significant disadvantage of the tailless aircraft configuration lies in the absence of an aircraft rudder normally incorporated within the vertical tail section. The rudder is provided in conventional aircraft to provide a side to side or yaw moment to the aircraft in flight. Therefore, without a rudder, other means must be provided to impart yaw moment to the tailless aircraft. Traditionally, tailless aircraft use spoilers in the outboard part of the wing. Either the left side or the right side can be made to open to control the lateral direction of flight. These spoilers are either made a part of the existing elevons, elevators or ailerons in the form of split flaps or they are mounted ahead of these surfaces in the form of inlay-spoilers. Elevons, ailerons and elevators on all wing aircraft have a minimal contribution to radar cross section. The spoiler is the largest detractor of stealth because it forms acute angles with the surface it emerges from. Traditional inlay spoilers can be low in cross section if they are only opened on the top side. The wing itself masks the view from below. But a topside only spoiler of conventional design produces a down force and, if the spoiler is near the tip of a sweptback wing, the resulting force will pitch the airplane upward.
As such, based upon the foregoing, there exists a need in the art for an improved method and device, which improves aircraft yaw control characteristics without substantially interfering with the aircraft aerodynamic and radar detectability characteristics.